Conventionally, in order to allow a liquid crystal display to achieve excellent contrast, a biaxial birefringent optical film has been used as a retardation plate. In general, a biaxial birefringent optical film is produced by stretching an isotropic polymer film (see Patent Documents 1 and 2, for example).
Also, by stretching a uniaxial polymer film (see Patent Document 3, for example), it is possible to produce a biaxial birefringent optical film (see, Patent Document 4, for example). A liquid crystal display incorporating such a biaxial birefringent optical film can achieve excellent contrast. However, since the And values exhibited by the biaxial birefringent optical film are in only a narrow limited range, wide viewing angles in accordance with various mode types have not yet been realized sufficiently by the use of the biaxial birefringent optical film. Moreover, there has been a problem in that display coloring may be caused in a liquid crystal display, e.g., a VA mode liquid crystal display, incorporating the biaxial birefringent optical film.    Patent Document 1: JP 3(1991)-33719 A    Patent Document 2: JP 3(1991)-24502A    Patent Document 3: JP 8(1996)-511812 A    Patent Document 4: JP 2000-190385 A